CAD/CAM (Computer-Aided Design/Computer-Aided Manufacturing) is used to obtain digital images of a target object. In the dental field, CAD/CAM technology is of particular importance. CAD/CAM systems, such as the CEREC (Chairside Economical Restoration of Esthetic Ceramics) System manufactured by Siemens Dental Products Division and the PROCERA A11-Ceram system of Nobel Biocare AD, are used to obtain optical impressions of cavity preparations for restorative work. These impressions can then be used for the manufacture of inlays, onlays, partial crowns, posterior crowns, anterior crowns and veneers.
The CAD/CAM camera takes a three dimensional image of the target area using infrared waves that are sent down to the area and back to the camera. An optical image is recorded with the 3D camera by projecting an invisible grid onto the field of view to record surface dimensions. As the grid is reflected off the surface, the camera interprets distortions in the grid as differences in height (Z values). The camera's field of view must have a uniform reflective surface to accurately record the height values. With respect to dental applications, computational analysis of the data captured by the optical image of a tooth allows for precise measurement of the heights of the structure, adjacent teeth and surrounding tissue. Accurate recording of the preparation is essential to effective application of the device.